Two-dimensional materials such as graphene and transition metal dichalcogenides (TMDCs) constitute a rapidly advancing class of materials for nanoscale device fabrication. TMDCs in particular—materials like WSe₂ or WS₂—have already enabled photodetectors with bandwidths reaching several hundred megahertz.

In my work, I aim to push these switching speeds even further by combining exfoliated TMDC crystals with plasmonic nanostructures to enhance the optical absorption. This is expected to increase the photocurrent in the semiconductor through mechanisms such as hot-electron injection or plasmon-induced resonant energy transfer (PIRET). At the same time, this photocurrent enhancement may also improve the device response time by reducing the effective resistance and thereby mitigating RC-time limitations.

To achieve this goal, a combination of fabrication and characterization techniques is utilized. On the fabrication side, I employ optical lithography, electron-beam lithography, and reactive-ion etching to create and define device structures. For optical characterization, I use photoluminescence, Raman, and absorption spectroscopy to assess material quality and optical responses. Electrical characterization includes I-V measurements, gate-dependent transport measurements as well as time-resolved intrinsic and extrinsic photocurrents.